1. Field of the Invention
The present general inventive concept relates to a disk drive apparatus and a method of controlling a disk drive apparatus, and more particularly, to a disk drive apparatus and method of adaptively controlling a flying height of a magnetic head over a disk according to a change in a user environment of the disk drive apparatus.
2. Description of the Related Art
Conventional disk drives have been disclosed in Japanese Laid-Open Patent Publication No. 2004-079126 and U.S. Patent Application Publication No. 2006-0119974.
Hard disk drives (HDDs) contribute to the operation of a computer system by reproducing/recording data from/on a disk using a magnetic head. Due to the recent demand on the HDDs with high capacity, high density, and compact size, more accurate mechanisms are required to increase a bit per inch (BPI) indicating the density in a rotational direction of a disk and to increase a track per inch (TPI) indicating the density in a radial direction of the disk.
Read/write performance of HDDs is influenced by a flying height of a magnetic head with respect to the surface of a disk. As the flying height of the magnetic head with respect to the surface of the disk decreases, the read/write performance increases. However, this may also increase the possibility that the magnetic head will collide against the surface of the disk. On the other hand, as the flying height of the magnetic head with respect to the surface of the disk increases, the possibility for collision between the magnetic head and the disk can decrease; however, the read/write performance decreases.
In order to determine a flying on demand (FOD) power value used to adjust a target flying height, a flying height profile of the magnetic head in accordance with a change in FOD power is obtained through a touch down test in a burn-in test of a HDD.
When the HDD operates according to user conditions, a normalized flying height profile at a temperature detected based on the user conditions is obtained by reflecting a correction value in accordance with a change in a temperature statistically obtained from a flying height profile obtained at a single temperature during the burn-in test.
However, when the flying height profile is normalized in accordance to the temperature based on the statistical method, HDDs vary depending on the component characteristics and assembled states. Accordingly, a conventional apparatus and method can not obtain an optimal flying height profile for each of the HDDs according to the user environment.